I own a 1993 prostar190 I keep it on the lake full time. I pull it out about once a month to clean the hull. I notice this last time ,what seems to be small blisters on the bottom left side of the hull. What could be the cause of this and can I repair or be concerned.

I own a 1993 prostar190 I keep it on the lake full time. I pull it out about once a month to clean the hull. I notice this last time ,what seems to be small blisters on the bottom left side of the hull. What could be the cause of this and can I repair or be concerned.

It's a well-known problem for boats kept in the water.

In the 1993 owner's manual for your boat, MasterCraft mentions blistering of the gelcoat on boats left in the water for extended periods and they specifically exclude gelcoat blistering from their lifetime hull warranty. They recommend a good quality bottom paint to minimize that problem.

Thanks for the info. I'll look into doing that over the off season after Labor day. I Love my MC and plan to keep it in mint condition. I have a place at Lake Hartwell in Georgia and paln to have a lift in my dock by next spring. That should help also.

Bottom paint is a well known way to stop blistering.
But it also immediately destroys the resale value of your boat.

Using a lift should keep the blisters at bay as it allows the gelcoat to dry, and essentially like using a trailer, just be sure to lift it all the way up.

There was a post here awhile ago from juju151 that developed blistering exactly where his hull rested on the carpeted bunks of his trailer. On my boat lift, I have full-length ridged poly bunks, so no holding water next to the hull.

This is some thing I don't understand, boat is made to be put in the water. Yet the industry are telling us not to do that so often cause it will cause blister to the bottom of the boat. I think boats that has blisters to the bottom are those that has its bottom redone at the factury or some time before the customer bought it. When that happen, the quality of the new paint or gel coat does not have the same quality as the first gelcoat and that caused blisters. Just a thought.